Polymer or hydrogel-coated substrates are used in many technological applications. For example, implantable medical devices can be coated with biologically inert polymers. In another example, polymer or hydrogel coated substrates are used for the preparation and/or analysis of biological molecules. Molecular analyses, such as certain nucleic acid sequencing methods, rely on the attachment of nucleic acid strands to a polymer or hydrogel-coated surface of a substrate. The sequences of the attached nucleic acid strands can then be determined by a number of different methods that are well known in the art.
In certain sequencing-by-synthesis processes, one or more surfaces of a flow cell are coated with a polymer or a hydrogel to which nucleic acids are attached. Current commercial flow cells utilize a non-attached gel coating. Use of an appropriate conjugating chemistry may provide for commercially viable flow cells having covalently attached gel coatings. Considerations such as cost of materials, compatibility with manufacturing processes, stability during storage and shipping, and the ability to support downstream chemical processing steps such as nucleic acid amplification and sequencing are important to consider. This disclosure provides a particularly useful chemistry having several advantages as will become apparent from the disclosure.